Self-Assembly of Crystalline Vesicles from Nonplanar pi-Conjugated Nanocycles

There is a great demand for self-assembled carbon nanomaterials because of their importance in optoelectronics, biomaterials, and so forth. Herein, we report a novel type of self-assembled, nanoscale, crystalline vesicle from nonplanar pi-conjugated nanocycles. We designed four different structural [8]cycloparaphenylenes ([8]CPPs) molecules and demonstrated that these nonplanar pi-conjugated CPP nanocycles could self-assemble into multilamellar, crystalline vesicles in tetrahydrofuran (THF)/H2O mixed solvent. The critical driving force for the assembly of nanoscale CPP vesicles is crystallization and pi-pi interaction of nonplanar, nanocyclic molecules. The size of CPP vesicles could be regulated by changing water content, temperature, and concentration in solution. Our data demonstrate that these pi-conjugated nanocycle-based vesicles show a remarkable ability to enter cells in an energy- or temperature-independent manner and kill cancer cells. When the side groups of the CPP molecule were changed, the CPP vesicles showed a large difference in the cytotoxicity, and two CPP vesicles could effectively kill cancer cells as well as first-class antitumor agents.

Automated summary

This study demonstrates that nonplanar pi-conjugated nanocycles can self-assemble into crystalline vesicles, with the size of vesicles being adjustable in solution. The vesicles show a remarkable ability to enter cells and kill cancer cells, making them potential candidates for effective anti-tumor agents.